Results from an ongoing survey of Minnesota National Guard troops conducted by researchers at the Minneapolis VA Medical Center show that most cases of mild brain injury or concussion are likely to fade over time.
Researchers say the survey, which was published in the January issue of Archives of General Psychiatry, also sheds more light on post-traumatic stress symptoms.
The findings could be good news for the thousands of Iraqi and Afghanistan veterans believed to have suffered mild brain injury during combat, although it's unclear how many troops have come home with TBI.
Minneapolis VA Medical Center psychologist Melissa Polusny says the number of soldiers who report an injury that made them feel dazed or confused, or forced them to lose consciousness, varies widely.
Polusny and her colleagues surveyed more than 950 Guard soldiers, and in one survey, as many as 22 percent of them reported suffering a mild traumatic brain injury while deployed.
"When someone hears the word brain injury, I think they make assumptions about what that is," she said. "What we are talking about is concussion, which is sometimes referred to as mild traumatic brain injury."
Mild traumatic brain injury differs from moderate to severe TBI. Polusny says there are a number of common symptoms.
"Like headache, or difficulty concentrating, or irritability or memory difficulties, maybe ringing in the ears or tinitis," she said. "These are grouped together and referred to as post-oncussive symptoms."
The survey followed National Guard soldiers who served in Iraq in 2006 and 2007. Researchers were looking at the associations between concussion and PTSD symptoms, and whether mild TBI caused long-term effects.
Polusny says the results were conclusive.
"There wasn't really any strong evidence for long-term negative impact of concussion or mild TBI history alone, when you didn't take into account the effects of PTSD," she said.
The study found that mild TBI does not further aggravate symptoms of post-traumatic stress. Polusny says in fact, it shows that some service members may be attributing their symptoms to brain injury when they could really be caused by PTSD.
That's the case with Minnesota National Guard veteran Ed Yurick, who was convinced something was wrong when he returned from Iraq in 2007.
More than three years later, he still has trouble concentrating and remembering things. At first, he says doctors told him he had traumatic brain injury, or TBI. But now they think otherwise.
"They apparently don't think I do have TBI. They think I have symptoms of that, but they think it's more the PTSD," said Yurick.
He gets frustrated when he comes back from the store empty-handed or can't focus.
"Concentration is the biggest thing for me," he said.
While the survey did not address whether people with repeated mild concussions, or moderate or severe head injury, may have problems down the road, Polusny says she hopes these findings on mild TBI could help more service members get appropriate treatment.